The department of the treasury's office of Foreign Assets Control designated Chhota Shakeel and Ibrahim "Tiger" Memon as Specially Designated Narcotics Traffickers for their roles as part of 'D Company', a criminal group run by Dawood.
It said Mumbai-born 57-year-old Chhota Shakeel is Dawood's lieutenant who coordinates for D Company with "other organised crime and terror groups."
The department said Memon, 52, is a trusted lieutenant of Dawood and controls D Company's businesses across South Asia and is also wanted by India for his involvement in the 1993 Mumbai bombings that killed more than 250 people.
"Treasury continues to target the nexus of crime and terrorism in South Asia with today's action against one of the world's most notorious criminal organisations," said OFAC director Adam Szubin.
Interpol has issued provisional arrest warrants or "red notices" for both Shakeel and Memon.
Dawood was named as a Specially Designated Global Terrorist in October 2003, and in June 2006, he was named as a drug trafficker.
Also in June 2006, the Dawood group was named as a Significant Foreign Narcotics Trafficker.